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Need Help With Math Homework (Inverse of Matrices)
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| Pariah Cleric |
Okay, I'm total e with math,if anyone remembers how to do this stuff, I need to find the inverses of matrices, if there is one in the problem.
Can anyone do one as an example and just show me what to do?
5 0
0 1 |
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| Basstard |
| quote: | Originally posted by Pariah Cleric
Okay, I'm total e with math,if anyone remembers how to do this stuff, I need to find the inverses of matrices, if there is one in the problem.
Can anyone do one as an example and just show me what to do?
5 0
0 1 |
-1 0
0 -5
its been 4 years since ive did them but im pretty sure thats how its done |
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| sensorium |
EDIT: :whip:
[5 0] [x11 x12] = [1 0]
[0 1] [x21 x22] [0 1]
[5x11 + 0x21 5x12 + 0x22 ] = [1 0]
[0x11 + 1x21 0x12 + 1x22 ] [0 1]
5x11 + 0x21 = 1 5x12 + 0x22 = 0
0x11 + 1x21 = 0 0x12 + 1x22 = 1
5x11 = 1 5x12 = 0
1x21 = 0 1x22 = 1
x11 = 1/5, x21 = 0, x12 = 0, x22 = 1
[1/5 0]
[0 1]
check:
[5 0] [1/5 0] = I
[0 1] [0 1]
[5(1/5)+0 0+0] = I
[0+0 0+1]
[1 0] = I
[0 1] |
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| Marc Summers |
Math is gay! I will never do another math problem!
Thank you H&R Block! |
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| ::TranceVanDyk:: |
at the bottom in quotes is how to do it, in simple terms.
what kind of inverse are u trying to find? there is additive, and multiplicative inverses, and both are different. the obvious is additive, where u take the original matrix, add it by its inverse to get all zeros in the answer. with a multiplicative inverse, u make the original matrix multiplied by its inverse = to
[1 0]
[0 1]
make it into an algebraic equation. matrix A (x or +) matrix (inverse which is unknown) = (0 1 0 1 matrix for multiplicative) or (matrix with all zeros for additive)
hope u know what identity and all that is.
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take a graphing calculator, preferably a texas instrument TI-83+.
enter the values into a matrix in the calculator. if u dont know how to do that, find out.
then get matrix A, which is the values for your matrix, and just put a -1 as its exponent, and youll get your answer.
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| quote: | Example 1: Find the multiplicative inverse of 
Find
click this link for an example of multiplicative inverse shown simply |
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| LeopoldStotch |
matrices are essential in life.
without matrices, you will not have your rpg video games.
without matrices, there would be no world of warcraft and unreal tournament.
by the way :
[5 0] | [1 0]
[0 1] | [0 1]
==
[((5*1)+(0*0)) ((5*0)+(0*1)) ]
[((0*1)+(1*0)) ((0*0)+(1*1)) ]
==
[5 1]
[0 1] |
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| sensorium |
[5 0] [x11 x12] = [1 0]
[0 1] [x21 x22] [0 1]
[5x11 + 0x21 5x12 + 0x22 ] = [1 0]
[0x11 + 1x21 0x12 + 1x22 ] [0 1]
5x11 + 0x21 = 1 5x12 + 0x22 = 0
0x11 + 1x21 = 0 0x12 + 1x22 = 1
--------------- ---------------
5x11 + 1x21 = 1 5x12 + 1x22 = 1
:whip: :stongue: |
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| sensorium |
| quote: | Originally posted by ierxium
[5 0] [x11 x12] = [1 0]
[0 1] [x21 x22] [0 1]
[5x11 + 0x21 5x12 + 0x22 ] = [1 0]
[0x11 + 1x21 0x12 + 1x22 ] [0 1]
5x11 + 0x21 = 1 5x12 + 0x22 = 0
0x11 + 1x21 = 0 0x12 + 1x22 = 1
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5x11 = 1 5x12 = 0
1x21 = 0 1x22 = 1
x11 = 1/5, x21 = 0, x12 = 0, x22 = 1
[1/5 0]
[0 1] |
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| sensorium |
check:
[5 0] [1/5 0] = I
[0 1] [0 1]
[5(1/5)+0 0+0] = I
[0+0 0+1]
[1 0] = I
[0 1]
:) |
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| ::TranceVanDyk:: |
| fellas, we are genious;) |
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| UWM |
| quote: | Originally posted by ::TranceVanDyk::
fellas, we are genius;) |
Fixed. |
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| Pariah Cleric |
| Thanks a ton, guys. It's actually really simple, the book we have just makes it crazy hard to understand. |
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